A/N: So, this is my first foray into ffnet! Woohoo! Figured it's only natural to start off with something sad. This was based off a prompt on avengerkink that asked for Thor dealing with the deaths of his comrades. This was pre-Thor:TDW, so Frigga is alive and Thor is for all intents and purposes, immortal.

It was October when I wrote it, so breast cancer was at the forefront of my mind. Many women in my family have been claimed by this disease, and I wanted to express my frustrations with it and this kind of just took off. The next chapters will deal with deaths of other comrades in other sad ways, so please regard the genre and strap yourselves in for some good old fashioned sad.

A Note Unsaid

Chapter 1: Natasha

Natasha is the first, and Thor is not prepared.

He has no disillusions about Midgardians. He knows their lives are fleeting compared to his own. It's perhaps part of why he originally found them so fascinating, that they live with such passion and tenacity, defiant to their impending doom. He's never known such liveliness on Asgard, and he gravitates to it like a moth to a flickering flame.

In his realm, lives are simple. People live for glory, for their names in songs of battles fought and victories won. Here, they live for something more. Here, they live for meaning, and they're fickle and restless in their pursuit. They question everything, yet they believe so fiercely in ideas and faiths and principles they want so desperately to be true. Thor cannot fully comprehend the thoughts of these Midgardians, but he's seen enough to be envious of them. Their mortality limits them, but it also makes them precious to each other in a way that he will never know. Thor finds it beautiful.

Until Natasha is diagnosed with the Midgardian ailment known as "cancer" and mortality suddenly and completely loses all romantic appeal.

Thor has heard of the disease in his time spent on Midgard - hard to avoid it, really, with so many in the realm affected by one or many of its forms- but he doesn't understand the true danger of it until he sees the faces of his fellow Avengers as the regal Widow explains her condition.

She's been struck with a rare and persistent strain of the disease- inflammatory breast cancer, a term forever seared into his mind- and the outlook is grim. Her physiological enhancements have left her immune to most mortal ailments, but evidently cancer is not so easily prevented.

Tony is not surprisingly the first to react. He immediately assumes financial responsibility for Natasha's treatment, having JARVIS dial the home numbers of every top oncologist in the world as he abruptly leaves the room. No one is bothered by the brusque departure. Bruce asks Natasha what treatments she's considering. Steve asks how she's doing and assures her the entire team will support her in her fight. Clint says nothing, but it's clear that he doesn't need to. Thor's known the two warriors long enough to know that Natasha would have told Clint of her illness long before anyone else. The Hawk has already asked his questions and is offering his support to Natasha now in his own way, watching over her as the rest of their chosen family try to adapt to this devastating news.

Thor doesn't know what to say. He doesn't know the right questions to ask, can't comprehend such awful words as modified radical mastectomy. Then the solution occurs to him, and he could kick himself for taking so long to respond.

"I shall take you to the healers of Asgard," he announces, and they all turn to look at him. He expects to see relief on Natasha's beautiful face, but the smile she returns to him is only one of pity. He opens his mouth to repeat himself because surely she must have misheard him to not be filled with joy at such a proclamation when the Hawk finally speaks.

"Afraid that's a dead end for us, big guy," Clint explains, blunt and matter-of-fact as when in battle. "Our guys tried to commission your healers for a cure for cancer years back when we first established diplomatic relations. But all their treatments were either useless or just made things worse."

Thor gets the irrational urge to strike out at the Hawk for his rebuttal. The healers of Asgard are the best in all the Nine Realms. How dare he call their efforts useless, this mortal? But all anger slips out of him when he looks in the Hawk's eyes for the first time since news of Natasha's illness was broken. Clint looks bitter and resigned, and Thor cannot bring himself to lash out. He can only lay a single, gentle kiss to Natasha's cheek before taking his leave.

"I shall return," he vows on his way out. He calls on Heimdall to return him to his Asgard to consult with his mother, the most gifted healer he knows.

To Thor's great disappointment, she can only corroborate Clint's assertion.

"We are trained to restore, but this affliction is strange to us," Frigga explains. "This disease consumes the body, but the parts that consume are of the body itself. They are borne not of poison, nor of infection. Such occurrences within the body are unknown to our people. I am sorry, my son."

It is the greatest defeat Thor has ever known to return to Midgard with no cure for his cherished friend. He is as useless as the healers of Asgard to Natasha, and it takes all his bravery and might to stay by her side in the ensuing months of her treatment.

Only days after announcing her illness, Natasha begins chemotherapy. The way it's explained to Thor makes it sound horribly archaic and unpleasant, yet all he can do is sit with his fellow warrior while a machine pumps poison into her body, hold a bucket for her while she vomits, and pray to the Allfather that her suffering won't be for naught.

The doctor's seem tentatively pleased with Natasha's reaction to months of the awful chemotherapy, which fills Thor with joy until he hears how they plan to mutilate her. It seems cruel and barbaric, to cut away so much of his dear friend, but all the experts Tony has assembled are in agreement that it is the best hope they have for her survival.

She and Clint kiss before she goes under for surgery, an out-of-character gesture for the normally stoic and pragmatic couple that no one comments on.

The surgery goes well, Thor is told, and while Natasha recovers in a customized suite Tony installed in the Tower, he spends as much time as possible by her side. Between the five of them, she rarely has a moment to herself, but she doesn't seem to mind the company. She endures radiation, another treatment Thor has come to loathe, with grace and dignity that belie her weakened state. Her fiery red hair is gone (she had Clint help her shave it all off before even starting chemotherapy), her skin is pale and waxy, and the surgery has given her a look of frailty that makes her almost unrecognizable to Thor at times. He finds it ironic that only with her feminine attributes- always her most powerful weapons against those who would underestimate her- gone does she truly seem vulnerable.

Six weeks after Natasha's surgery, they are told that her prognosis is "very positive." The feeling of relief is staggering, the first gulp of fresh air after minutes underwater.

Normalcy begins to creep back into their lives as Natasha's condition improves, but evidence of her trials linger. Tony operates a pink Ironman suit. Bruce makes macrobiotic meals every day. Clint is affectionate, and Natasha not only allows it, but reciprocates as well. Thor never sees the two not touching in some way, but these touches are nothing like the casual displays he'd previously associated with the couple. These are soft, intimate gestures he never would have thought the assassins capable of demonstrating so openly, but then again he's always being surprised by these Midgardians.

Six months later, Natasha's prognosis changes.

They are told that the initial treatment was thought to have severely reduced the chance for advanced metastasis, but that her body has stopped responding favorably to treatment. The doctors' expressions are clear, and even as they explain the possible treatment options that remain for their patient, it's clear even to Thor that they hold no real hope for her survival.

The realization that his friend, his comrade, his shield-sister, his Natasha, is in fact going to die, not of a mortal battle wound like he thought- like he so selfishly wanted- but of this wretched disease fills him with righteous fury because it's just not fair. Natasha, the lethal Black Widow, deserves more. It's an injustice, an egregious error by the fates that this fierce, brave, witty, charming, wonderful woman would be sentenced to wither away in pieces rather than die fighting.

And he's never wanted so badly to lay waste to a nonliving thing as he does to this disease, this cancer that mutilated his friend and then cruelly tricked them all into thinking it had perished before returning to claim her life. But he cannot. The Son of Odin cannot lay waste to cancer. He can only weep for the loved one it has claimed.

There's aggressive questioning, which quickly escalates to yelling, first at the doctors and then at each other and then at the world, before the doctors leave and then there are only tears. Thor is openly sobbing against the wall he buried his fist into when the verdict was dealt. Tony has his arms crossed and is facing the window, shoulders trembling. Steve is collapsed into a chair with his head in his hands, sniffling quietly. Bruce is rubbing at his glasses and blinking away tears that won't stop coming.

Clint and Natasha are seated, wrapped around each other, completely silent and motionless. They both have tears streaming down their faces, but neither move to wipe them away.

They stay like that for hours, together in one room with their grief, before Natasha finally speaks, making it clear that she intends to go no further with chemotherapy and radiation. No one argues with her, but the words seem to strike at Clint like a blow. She then announces she's going to bed, and Clint follows her. They all retire eventually, but Thor finds no rest in his bed. Even if he could sleep, it would be to no avail. Natasha would still be dying in the morning, and he would still be powerless to stop it.

Natasha comes to terms with her condition long before anyone else. There's a serenity that surrounds her now that her end is imminent- a calmness- and Thor tries to find comfort in it. Tries to imagine that Natasha is prepared for her death and at peace with it, unable to conceive such a thing for himself. She now looks more like the Black Widow that she has since the horrible illness struck, which should also be a comfort, but only serves to depress him further. She asks Tony if she and Clint can borrow one of his jets, and the couple spends the next six weeks travelling the world. Tony tracks where they go. Some of the places they know; others will only ever hold significance to the two lovers. Their final and longest stay is in Russia, and when they return as if from a mission, covered in cuts and bruises, no one comments. Whatever the two did seems to have satisfied Natasha's need for absolution because she spends the rest of her days in New York with the rest of the team. They watch movies, play drinking games with authentic Russian vodka, and eat five star cuisines via delivery while Natasha waits to die.

When it becomes clear that she has little time left, each member of the team goes to Natasha individually to say goodbye. Thor plans to regale her with tales of their greatest adventures together, but when he enters the room, all he can say is,

"I regret that we did not have more time together, my dear friend."

"Us mortals have to take what we get, I guess," she retorts with eyes soft and sympathetic.

"It is hard for me to come to terms with this," Thor chokes out. "To lose you in this way-" He breaks off abruptly, unable to form the words.

Natasha smiles, gets a faraway look in her eyes and responds, "You know, I have to admit, I never wanted to go this way. I don't think anyone does. But the way it happened…I never thought I'd get to go back like I did. Never thought I'd see it coming with enough time to say goodbye. And now that I have, I wouldn't have it any other way. It's more than I ever would've dared to hope for."

Natasha dies two days later, surrounded by the people who loved her. Her death is anticlimactic, an exhale of breath that never returns followed by the somber announcement from JARVIS that her vital signs have ceased. Thor presses a kiss to her cooling brow and strokes her short sporadic bursts of red hair one last time, committing the color to memory forever.